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lemons, the common sweet orange being exempt. It occurs in 

 the United States, Australia, and Japan, from which latter 

 country it was probably introduced into America. It causes 

 small excrescences to appear on the young leaves and fruit. 

 These excrescences are at first of a pale, watery green colour, 

 but soon become coated with a dusky fungous growth composed 

 of a species of Cladosporium (the parasite which causes the 

 disease). The tissues of the warts infested by the fungus are 

 cat off from those below by. a formation of cork which ulti- 

 mately becomes so abundant as to give the excrescence a grey 

 colour. The full grown warts are l/25th to l/4th of an inch in 

 diameter and are often confluent. When attacked while still 

 very young the leaves and fruits are greatly distorted by the 

 disease. In the fruit especially, the warts cause the tissues 

 below to grow too fast and to form large bumps. These with 

 the grey excrescences so disfigure the fruit as to render it 

 nearly valueless. The fungous parasite causing scab is able to 

 spread and infect new spots only during moist weather. For 

 this reason very dry regions are nearly exempt from the 

 malady. The loss from this disease results principally from 

 its action in disfiguring lemons. It does most harm in Florida, 

 where it causes an annual loss of not far from $50,000. The 

 disease can be prevented on lemons by spraying the young 

 fruits from three to five times with ammoniacal solution of 

 copper carbonate. 



4. Sooty Mould is a black fungus, which follows the attacks 

 of certain honey-dew secreting insects. It may be recognised 

 by the sooty black membrane which it forms principally over 

 the upper surfaces of the leaves, fruits, and stems. The 

 disease greatly reduces the productivity of the trees, and the 

 oranges formed are so badly disfigured by the covering of sooty 

 mould as to be rendered unsaleable. The annual loss in 

 Florida is not far from $50,000. Thorough spraying with resin 

 wash has been found very effective. Between December and 

 March of each year three sprayings should be made. Fumiga- 

 tion with hydro-cyanic gas has also been found an effective 

 remedy. The applications should be made during the winter. 

 A parasitic fungus has been found which promises to be a very 

 great aid in combating this malady. 



5. Foot Rot or Mal-di-Gomma is the most wide spread of 

 all orange disease. The total damage which it causes is greater 

 than that resulting from any other one malady, in Florida 

 alone, amounting to nearly $100,000 annually. It may be 

 recognised by the exudations of gum from definite patches of 

 the tree near the base. A separative layer is formed by the 

 tree deliminating the diseased bark ; the edges of the bark 



